1. Field of the Invention
This invention relates to a control system for internal combustion engines, which detects heat flux within the combustion chambers of the engine and controls the combustion efficiency of the engine, based on the detected heat flux.
2. Prior Art
Conventionally, a control system for internal combustion engines is known, for example, from Japanese Laid-Open Patent Publication (Kokai) No. 3-199651, which directly measures the heat amount of gases flowing into a combustion chamber of the engine by a heat flux sensor arranged in the combustion chamber, and estimates a cooling loss from the measured heat amount, to thereby accurately carry out air-fuel ratio control based on the temperature of exhaust gases emitted from the engine.
Further, an internal combustion engine has been proposed, for example, by Japanese Patent Publication (Kokoku) No. 61-51650, in which a sensor for detecting the temperature of a combustion chamber of the engine is mounted in the wall of the combustion chamber, and the maximum allowable value of an amount of fuel supplied into the combustion chamber is changed according to a change in the temperature of the combustion chamber.
Neither of the above-mentioned prior art techniques, however, controls a combustion in the same cycle of the engine as the cycle in which the parameter is detected by the sensor, based on the detected parameter, but they control combustions over several cycles of the engine, based on the detected parameter, i.e. they control the engine combustion on a macro basis. Therefore, the prior art techniques fail to perform so-called micro control that the combustion in the present cycle is controlled in response to an amount of residual gases within the combustion chamber in the last cycle. As a result, the combustion efficiency of the engine cannot be improved with high responsiveness to the actual amount of residual gases within the combustion chamber.